<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    
</body>
<script>

    // var obj = {};
    // var obj2 = new Object();
    // console.log(obj)
    // console.log(obj2)


    var obj = {
        a:10,
        b:20,
        c:30
    };

    obj.name = "admin";
    obj.name = "root";
    obj.age = 19;
    obj.sex = "男";
    obj.msg = "hi";

    delete obj.name;
    delete obj.sex;
    delete obj.age;
    delete obj.msg;

    console.log(obj.name);
    console.log(obj.age);
    console.log(obj.sex);
    console.log(obj.msg);

    console.log(obj);

    
</script>
</html>